Access to Node.js

We are using apache-php for all of our virtual sites which are setup and configured with IPSConfig3. Now we would like to use Node.js for some sites alongside apache, particularly for HTML5 push requests (EventSource) where apache-php may not be the best solution. Installing the node.js and NPM libraries is not a big problem on our Ubuntu server, but I'm not clear about the best way to make node.js and javaScript modules running under node.js available to our virtual sites. We don't want to setup a completely different server as, at least, for the moment we want to continue using a big part of our existing php lib; it would be very expensive and time consuming to port everything. So the idea is to only use node.js where we need a continuously open connection and pipe requests (http requests if using apache or pehaps cdi php requests if not) to and from node.js as required.

So has anybody already done this?
How should we config Ubuntu/ISPConfig3 if it is indeed possible?
Any ideas would be very welcome